build: [gn] explicitly override rtc_use_h264 (#14378)

* build: [gn] explicitly override rtc_use_h264

* build: [gn] don't override ffmpeg config from release config

* build: [gn] remove is_cfi override from release config

The original concern about node is fixed and we have been
building testing builds without the override for sometime now.

build/args/debug.gn

@@ -1,3 +1,10 @@
 import("all.gn")
 is_debug = true
 is_component_build = true
+
+# This may be guarded behind is_chrome_branded alongside
+# proprietary_codecs https://webrtc-review.googlesource.com/c/src/+/36321,
+# explicitly override here to build OpenH264 encoder/FFmpeg decoder.
+# The initialization of the decoder depends on whether ffmpeg has
+# been built with H.264 support.
+rtc_use_h264 = proprietary_codecs

build/args/ffmpeg.gn

@@ -1,3 +1,6 @@
-import("release.gn")
+import("all.gn")
+is_component_build = false
+is_component_ffmpeg = true
+is_official_build = true
 proprietary_codecs = false
 ffmpeg_branding = "Chromium"

build/args/release.gn

@@ -4,6 +4,9 @@ is_component_ffmpeg = true
 is_official_build = true
 strip_debug_info = true
 
-# TODO(nornagon): linking non-CFI code (nodejs) with CFI code fails at runtime.
-# Once we can build nodejs with CFI flags matching Electron's, remove this.
-is_cfi = false
+# This may be guarded behind is_chrome_branded alongside
+# proprietary_codecs https://webrtc-review.googlesource.com/c/src/+/36321,
+# explicitly override here to build OpenH264 encoder/FFmpeg decoder.
+# The initialization of the decoder depends on whether ffmpeg has
+# been built with H.264 support.
+rtc_use_h264 = proprietary_codecs

build/args/testing.gn

@@ -5,4 +5,10 @@ is_component_ffmpeg = true
 is_official_build = false
 dcheck_always_on = true
 symbol_level = 1
-is_component_ffmpeg = true
+
+# This may be guarded behind is_chrome_branded alongside
+# proprietary_codecs https://webrtc-review.googlesource.com/c/src/+/36321,
+# explicitly override here to build OpenH264 encoder/FFmpeg decoder.
+# The initialization of the decoder depends on whether ffmpeg has
+# been built with H.264 support.
+rtc_use_h264 = proprietary_codecs